Face bow



C. E. STUART Nov. 23, 1965 FACE BOW Filed Dec. 16, 1963 4 Sheets-Sheet 1 INVENTOR. CHARLES Srumer BY Arm/ems) C- E. STUART Nov. 23, 1965 FACE BOW 4 Shets-Sheet 2 Filed Dec. 16, 1963 INVENT OR. 674,424.55 E. 570,427 x @541 ATI'UEA/E) C- E. STUART Nov. 23, 1965 FACE BOW 4 Sheets-Sheet 3 Filed Dec. 16, 1963 l lll [III INVENTOR.

Omens 571mm 5 K M A rmen/E Nov. 23, 1965 Filed Dec. 16, 1963 c. E. STUART 3,218,716

FACE BOW 4 Sheets-Sheet 4 245 INVENTOR.

CHAELES E 5214427 ATTORNEY United States Patent 3,218,716 FACE BOW Charles E. Stuart, R0. Box 891, Ventura, Calif. Filed Dec. 16, 1963, Ser. No. 330,762 7 Claims. (CI. 32-20) This invention relates to a face bow, this application being a continuation-in-part of my pending application, Serial No. 277,309, filed October 1, 1962, and titled Method and Apparatus for Guiding the Interplay of the Cusps of Human Teeth.

The said application relates to a method and apparatus to establish the disposition of a bite fork relative to the orbital plane of the human head and to transfer the same to an articulator so that the tooth impressions on said fork guide the mounting, on said articulator, of a model of the upper teeth of said head in the same relationship to the transferred orbital plane on the articulator as the teeth have to the orbital plane of the head. Said method and apparatus thereby enable an accurate relationship to be established between said model of the upper teeth and a model of the lower teeth, and afford a method and means for studying the relationship, under all relative positions of said models in simulation of the jaw movements of said head, of the interplay of the cusps of the teeth of said models.

An object of the present invention is to provide a novel face bow that is engaged with the depressions, anterior and medial, of the tragi of the ears and with the nasion of the head, to establish an orbital plane on said bow in relation to a bite fork carried by the bow. Since the mentioned ear depressions are only approximately one-quarter inch posterior to the condyle joints of the jaw from which the true auriculo-infraorbital plane extends, to approximately one inch below the naison, the orbital plane established with said depressions as the primary reference, rather than the condyle joints (which are hidden), provides a reasonably accurate reference plane for the purposes of this invention.

It has been common practice to use the auditory meatuses and to engage the same with ear plugs to establish the reference of a face bow to an orbital plane. Since such meatuses are approximately one-half inch from the condyle joints of the jaw, the provision of a face bow designed to engage the tragi has substantial advantages as regards effecting an accurate transfer of an orbital plane because it has initial reference on points materially closer to the condyle joints than are the auditory meatuses.

Another object of the invention is to provide a face bow, as characterized above, that is convenient and easy to apply to the skull, adjustable thereto with easy facility, and retentive of its adjusted condition while being moved from the skull to operative position on an articulator.

This invention also has for its objects to provide such means that are positive in operation, convenient in use, easily installed in a working position and easily disconnected therefrom, economical of manufacture, relatively simple, and of general superiority and serviceability.

The invention also comprises novel details of construction and novel combinations and arrangements of parts, which will more fully appear in the course of the following description, and which is based on the accompanying drawings. However, said drawings merely show and the following description merely describes, preferred embodiments-of the present invention, which are given by way of illustration or example only.

In the drawings, like reference characters designate similar parts in the several views.

FIG. 1 is a side elevational view of a face bow according to the present invention, and shown in operative "ice association with a human head to establish the orbital plane while impressions of the teeth are being made on a bite fork, mounted on said face how, by the teeth of said head.

FIG. 2 is a plan View showing the face bow of FIG. 1 mounted on an articulator, according to the invention.

FIG. 3 is a side elevational view of the face bow and articulator and showing the establishment of the orbital plane of the face bow on the articulator and the manner of mounting a model of the upper teeth in proper relationship to the articulator.

FIG. 4 is a bottom plan view as taken on the line 44 of FIG. 3, and showing one form of condyle-jointsimulating means.

FIG. 5 is a top plan view of a modified form of condyle-joint-simulating means.

FIG. 6 is a bottom plan view thereof.

FIG. 7 is an elevational view as seen from the left of FIG. 3.

FIG. 8 is a vertical cross-sectional view as taken on the line 88 of FIG. 3.

FIG. 9 is a top plan view of another form of face bow according to the invention.

FIG. 10 is a side elevational View, partly broken away and partly in section, of the face bow shown in FIG. 7.

FIG. 1 shows a human face in which the tragus T is shown as posterior to a point C that represents the axis of the condyle joint, the depression anterior and medial to the tragus being indicated by a point A which, as can be seen, is but slightly posterior to the condyle axis C. Said figure also shows the nasion N of said face and the upper teeth D. The orbital plane P that is to be established by means of the present face bow and transferred to the articulator, is shown as extending from the point A, anteriorly, about one inch below the nasion.

The modification shown in FIG. 9 shows the condyle axis C, and the depression A that is anterior and medial to the tragus T, as before. In this view, the orbital plane P coincides with the general plane of the arms 11a of the face bow 10a. This view also shows the approximate relative location of the auditory meatus M of the ear.

The bow face, shown at 10 in FIGS. 1, 2 and- 3, comprises, generally, a pair of arms 11, a connecting bar 12 spacing said arms and on the ends of which the same are pivotally movable, a ball 13 on the end of each arm for entry into the mentioned depressions A with the bar 12 forward of the nose, means 14 to lock said arms 11 in adjusted relation according to the transverse spacing of the depressions A, a nasion gauge 15 carried by one of said arms 11 preferably at its pivotal connection with the bar 12, a laterally and angularly adjustable member 16 mounted on said bar 12, a member 17 carried by the member 16 and spaced one inch below the level of the nasion gauge 15, and a fitting 18 on the member 16 to mount a bite fork 19.

The arms 11 are substantially alike and, as seen in FIG. 2, are formed to accommodate the face between them when the balls 13 are entered, from each side, into the depressions A. The means 14 is shown as a clamp screw that locks the arms in such adjusted relation. For smaller heads, the pivots 20 of said arms on the ends of bar 12 may be selectively shifted to the holes 21, thereby affording a wide range of adjustment of the arms 11.

The nasion gauge 15 is shown as a finger 22 with a rounded edge 23, said finger being swingable on the axis of a stud 24 into contact with the nasion.

The member 16 comprises a rod 25 with a clamp fitting 26 that is engaged over the bar 12 and extends normal to said bar. The fitting is slidable along the bar to any desired adjusted position and is also rotatable aroundthe axis of said bar. The member 17 constitutes is provided with a clamp 28 that may tighten around a shaft extension 29 of the bite fork 19. The latter is more or less conventional, being covered by a wax coating into which impressions 30 are formed by the teeth D. It will be clear that the bite fork, since it is clamped by the teeth D and the teeth in the jaw, may extend at various angles with respect to the orbital plane P according to different craniornetry of different heads. When wing screw 31 is taken up, the adjusted angle of the bite fork is locked with relation to said plane P. In this condition, the face bow may be removed from the face and mounted on the articulator 32.

The arms 11a of the face bow 10a, shown in FIGS. 9 and 10, are pivotally connected at 20a on the ends of a bar 12a; the adjustment of said arms 11a may be made as before, and locked by the clamp screw 14a to retain the balls 13a, as adjusted. The nasion gauge 15a is shown as a block 23a with a curved face to fit the nasofrontal suture so as to bring the pin 2312 at a desired spacing above the bow arms 11a. Said spacing is fixed at the distance of one inch by the length of post 24a between its notched engagement 24b with the bar 12a and the axis of the pin 23b. A screw 24a is provided for locking the gauge 15a to the post 24a after suitable frontal adjustment of the latter. The bite fork 19 is mounted on the face bow 10a in a manner similar to the means 16 shown in FIGS. 1 and 3, the rod 25a being counterpart of the rod 25 shown in said figures.

As can be seen in FIGS. 2 and 9, the ends of the face bow arms 11 and 11a that mount the balls 13 and 13a, respectively, are inbent toward each other as well as return-bent toward the opposite ends of said arms, thereby allowing the arm ends to clear the tragi T when the face bows are being applied, as in FIGS. 1 and 10, and also, the bars 12 and 12a are of such length that the respective pairs of pivots and 20a are spaced apart a distance approaching the average spacing of the balls 13 and 13a, when the clamp screws 14 or 14a, as the case may be, lock the adjustment of the bow arms when applied to a skull of average width. While the balls 13 and 13a move in arcuate paths, during adjustment of the bow arms, around the pivots 20 or 20a, said paths are nevertheless closely equivalent to adjustment paths used in face bows that depend on straight-line movement of ear plug or skull-clamping devices. Hence, the present bow construction provides two simple bow arms which are adjustably mounted on spaced pivots, the adjustment of the arms automatically providing flatly arcuate and approximately parallel adjacent of the balls 13 or 13a toward and from each other.

It will be noted that the member 17 is omitted from the face how 10:: since the plane of the flat arms 11a of said bow is coincidental with the orbital plane Pa.

The articulator 32 comprises, generally, a base frame 33, a pair of condyle balls 34 extending fixedly upward from said base frame although the transverse spacing thereof may be adjusted, a pad 35 on said frame forwardly spaced from the condyle balls, a plate 36 for mounting a model 37 of the teeth D, stud-clamping means 38 on the rearward end of plate 36, a pair of fossae-like members 39 adjustably carried by means 38 and extending and laterally and in support engagement with the condyle balls 34, and means 40 to center the plate 36 relative to the base frame 32.

The base frame 33 is shown as a bottom horizontal plate 41 that is supported in level position by rear legs 42 and a clamp screw 43 that serves to lock the pad 35 in adjusted position on said plate 41. Said frame 33 is provided with vertical members 44 that extend upwardly 4 from the. rear portion of plate 41, and with a cross bar 45 across the top of said members 44. As viewed from the side (FIG. 3), said base frame is L-shaped. Screw seats at 46 (FIG. 7) indicate the transverse spacing adjustment of the condyle balls 34.

The pad 35 may be longitudinally adjusted along the frame plate 41 and, as above explained, locked in adjusted position by the clamp screw 43.

The plate 36 and means 38 thereof adjustably clamp laterally extending studs or trunnions 47, which are provided on the fossae-like members 39, in a manner to enable lateral adjustment of said members. With the members 39 supported on the condyle balls 34, the forward end of plate 36 extends in support contact with the domed top 27 of the member 17 when the balls 13 of the arms 11 of the face bow 10 are engaged against the outer lateral faces of the fossae members 39. To this end, each member 39 is provided with a lateral projection 48 that fits a recess provided in each ball 13, as may be seen in FIG. 4, the members 39 being laterally adjustable in the means 38, accordingly. It will be clear that the under face 49 of the plate 36 represents the transferred orbital plane P, since the same has the same relationship to the bite plate 19 when the face bow 10 is being used as in FIG. 1 and as in FIG. 3.

The model 37 is the conventional reproduction of the upper set of teeth of a mouth, having been previously prepared in the usual way.

As shown best in FIG. 4, each fossae member 39 has a generally rectangular form and a downwardly facing hollow 50 in which a cam or guide element 51 may be secured. As seen in said FIG. 4, the condyle balls 34 are spaced according to the cam edges 52 of said cams, it being understood that a group of differently designed cams for difierent condyle paths, and the cams or guides chosen, have the particular characteristics of the condyle joints. Reference is made to applicants Patent No. 2,816,360 in this connection. It will be noted that the projections 48 are offset rearwardly with relation to the condyle balls 34, when the latter hold the plate 36 in centered relation to said balls, as in FIG. 4. The degree of offset approximates the offset between the point A and the condyle axis C of FIG. 1. Thus, although the balls 13, when engaged with projections 48 of the articulator 32, are spaced from the dome 27 the same distance as the point A is spaced from said dome, the point of pivot of the plate 36 and the tooth model 37 carried thereby is the common axial center of the condyle balls. Hence, transferred orbital plane P pivots on. the true pivot although the transfer was made from the pivot A which is posterior to the true condyle pivot. FIG. 3 also shows that the fossae may be tilted on the axis of the trunnions 47 for rotational adjustment that is locked by the clamp means 38.

The modification of FIGS. 5 and 6 shows the fossaelike members 39 in a design that uses an angularly adjustable member 53 instead of a selective guide cam 51 of a group of different cams. Said member 53 may be locked to a base member 54 by means of a clamp screw 55. It will be clear that the member 53 will provide a cam face 56 that is adjustable to the desired tangential engagement with a condyle ball 34. In other respects, said fossae are similar to the earlier-described forms.

The means 40 may comprise a spring-biased detent 57 that is urged to resiliently engage a notch 58 in the frame bar 45, the same affording a reference that vertically aligns the plate 36 with the base plate 41.

The present method for establishing the proper relat-ionship of the models of both sets of teeth and to guide the interplay of the cusps of said teeth so they will have the same relationship and interplay when molded into dentures for use in the mouth, is practiced in the following manner, based on a face bow 10.

A bite form is first prepared, inserted in the mouth and gripped between the teeth. The fitting 18 is then loosely slid over the extension 29 of the bite fork. With the lock means 14 loosened, the balls 13 are inserted into the mentioned depressions in the ears that are anterior and medical to the tragi, so the bow may be swung on the horizontal pivot afforded by said balls on the axial points A and the gauge 15 swung into contact with the nasion N. In this position, the fitting 18 is tightened to clamp the same to the rod 25 of the member 16 and to clamp the extension 29 to said fitting. Since the dome 27 of the member 17 is spaced a predetermined distance below the level of said gauge, locking of the means 14 lock the face bow with the bite fork 19 in accurate relationship to the orbital plane P.

After first laterally adjusting the fossae members 39 so their outer faces 59 are spread according to the space across the balls 13 of the face bow, the latter is applied to the articulator by resting the end of the rod 25 upon the pad 35 of the articulator and engaging the recesses in the balls 13 with the lateral projections 48 of said fossae. The plate 36 is allowed to drop down on the dome 27 and any desired angular adjustment of the fossae may be made to bring the balls 13 and the condyle balls 34 in the plane of the under face 49 of the plate 36. Since the bite fork 19 is fixed to the member 16 and said member, by its clamp 26, is fixed to the bar 12, the relationship between said face 49, i.e., the original orbital plane P, and the bite fork 19 is retained, albeit the fork has a generally horizontal disposition rather than the angled position of FIG. 1.

If the face bow a is used, the procedure is much the same, except that plate 36 is allowed to drop onto the bar 12a, reference that is at the fixed one inch below the nasion gauge a, thus bringing the orbital plane Pa in the same relation to the pad 35 as before.

Whether the face how 10 or 10a is used, the impressions 30 in said bite fork 19 are now used for locating the model 37 on said fork in exactly the same relationship that the teeth D had to said fork when making said impressions. Now, the plate 60 is slid along the plate 36 and locked thereto by a clamp screw 61 to be approximately vertically aligned with the model 37. Then, plaster of Paris 62 is filled in between plate 60 and the model 37, as shown in FIG. 3. When said plaster is set, the bite fork is removed with assurance that the teeth of the model 37 have the same relationship to the orbital plane P on the articulator as the teeth D have to the orbital plane P of the head of FIG. 1.

Now, the model 63 of the lower teeth may be mounted on the base plate 41 of the frame 33 with the teeth thereof in interlocking relation with the teeth of model 37 as established by use of known techniques and employing a bite strip or sheet to establish desired clearance.

Although in the head the jaw and its teeth articulate relative to the teeth fixed in the head, the present articulator by the means of the condyle balls 34, supports the upper model 37 for articulative movement relative to the model 63. The effect is the same, since under control of the fossae devices 39, the interplay of'the teeth cusps, as guided by the cam faces 52 or 56, as the case may be, may be studied and correction made in the interrelationship of the models 37 and 63 before the final dentures are produced from said models.

The frame 32 is shown as gravitationally supporting the plate 36 and the fossae 39, but any desired means, such as magnetism, elastic bands, or springs, may be used to connect the frame 32 and said plate 36 and fossae 39 while providing for articulation, as above described, between the models 37 and 63. The articulator may be held in both hands and the models moved relatively, to study the interplay of the teeth from all sides.

While the foregoing illustrates and describes what is now contemplated to be the best mode of carrying out the invention, the constructions are, of course, subject to modification without departing from the spirit and scope of the invention. Therefore, it is not desired to restrict the invention to the particular forms of construction illustrated and described, but to cover all modifications that may fall within the scope of the appended claims.

Having thus described the invention, what is claimed and desired to be secured by Letters Patent is:

1. A face bow for establishing an orbital plane relative to a bite fork with impressions of the cusps of the upper teeth of a patient and for transfer of said plane to an articulator, said face bow comprising:

(a) two similar bow arms, each provided at one end with a fixed ball for insertion into the depressions anterior and medial to the tragi of the ears of said patient, said arm ends being inbent toward each other and return-bent toward the opposite ends of the arms to clear the tragi with the balls in the mentioned ear depressions,

(b) a bar connected by pivots at the ends thereof to intermediate portions of the bow arms, said pivots, thereby, being spaced apart by said bar, and

(c) means adjustably connecting the opposite ends of said how arms to lock the same and the balls thereof spaced according to the spacing in the patients skull of the mentioned depressions.

2. A face bow according to claim 1 in which the spacing of the pivots on the ends of the bar is such that the balls on the ends of the bow arms move toward and from each other in flatly arcuate and approximately parallel paths on said pivots during adjustment of the bow on the face of a patient.

3. A face bow for establishing an orbital plane relative to a bite fork with impressions of the cusps of the upper teeth of a patient and for transfer of said plane to an articulator, said face bow comprising:

(a) two similar bow arms, each provided at one end with a fixed ball for insertion into the depressions anterior and medial to the tragi of the ears of said :patient, said arm ends being inbent toward each other and returnbent toward the opposite ends of the arms to clear the tragi with the balls in the mentioned ear depressions,

(b) a bar connected by pivots at the ends thereof to intermediate portions of the bow arms, said pivots, thereby, being spaced apart by said bar,

(c) means adjustably connecting the opposite ends of said how arms to lock the same and the balls thereof spaced according to the spacing in the patients skull of the mentioned depressions, and

(d) a nasion gauge mounted on said bar in fixed spaced relation to the bow arms.

4. A face bow for establishing an orbital plane relative to a bite fork with impressions of the cusps of the upper teeth of a patient and for transfer of said plane to an articulator, said face bow comprising:

(a) two similar bow arms, each provided at one end with a fixed ball for insertion into the depressions anterior and medial to the tragi of the ears of said patient,

(b) a bar connected by pivots at the ends thereof to intermediate portions of the bow arms, said pivots, thereby, being spaced apart by said bar,

(c) means adjustably connecting the opposite ends of said bow arms to lock the same and the balls thereof spaced according to the spacing in the patients skull of the mentioned depressions,

(d) a nasion gauge mounted on said bar in fixed spaced relation to the bow arms,

(e) a bite fork, and

(f) means adjustably mounting the bite fork relative to the bar and the nasion gauge carried thereby.

5. In apparatus for providing a transferred orbital plane on an articulator in established relation to a bite fork with impressions of the cusps of the upper teeth of a patient,

(a) a face bow comprising connected and pivotallymounted arms,

(b) a ball at the end of each arm, said balls being adapted for insertion into the depressions anterior and medial to the tragi of the ears of said patient,

(c) a gauge carried by said arms for engagement with the nasion of the patient,

(d) means disposed in predetermined relation below said gauge and cooperating with said balls to define the orbital plane of the head of said patient,

(e) a bite fork adapted to be disposed between the teeth of the patient to provide therein indentations of the cusps of the upper teeth, and

(1?) means mounting and fastening the bite fork to the mentioned arms to retain the relative relationship of said plane and fork.

6. In apparatus according to claim 5, a transverse bar connecting said arms, and the fork-fastening means being mounted on said bar.

7. In apparatus according to claim 5, a transverse bar connecting said arms, the fork-fastening means being mounted on said bar and comprising a member longitudinally adjustable along and axially around said bar, and a fitting universally interconnecting the bite fork and the latter member.

References Cited by the Examiner UNITED STATES PATENTS 1,188,416 6/1916 Dalbey 3220 1,589,802 6/1926 Gould 32Q0 RICHARD A. GAUDET, Primary Examiner.

ROBERT E. MORGAN, Examiner. 

1. A FACE BOW FOR ESTABLISHING AN ORBITAL PLANE RELATIVE TO A BITE FORK WITH IMPRESSIONS OF THE CUSPS OF THE UPPER TEETH OF A PATIENT AND FOR TRANSFER OF SAID PLANE TO AN ARTICULATOR, SAID FACE BOW COMPRISING: (A) TWO SIMILAR BOW ARMS, EACH PROVIDED AT ONE END WITH A FIXED BALL FOR INSERTION INTO THE DEPRESSIONS ANTERIOR AND MEDIAL TO THE TRAGI OF THE EARS OF SAID PATIENT, SAID ARM ENDS BEING INBENT TOWARD EACH OTHER AND RETURNBENT TOWARD THE OPPOSITE ENDS OF THE ARMS TO CLEAR THE TRAGI WITH THE BALLS IN THE MENTIONED EAR DEPRESSIONS, (B) A BAR CONNECTED BY PIVOTS AT THE ENDS THEREOF TO INTERMEDIATE PORTIONS OF THE BOW ARMS, SAID PIVOTS, THEREBY, BEING SPACED APART BY SAID BAR, AND (C) MEANS ADJUSTABLY CONNECTING THE OPPOSITE ENDS OF SAID BOW ARMS TO LOCK THE SAME AND THE BALLS THEREOF SPACED ACCORDING TO THE SPACING IN THE PATIENT''S SKULL OF THE MENTIONED DEPRESSIONS. 